Transfform animation working on timeline's preview, but not in playmode

I've basically setup a humanoid character with some basic animations and an override track to set the posiition of the character in timeline, it works within the timeline preview but not in playmode.
I get a couple of warnings in the animator component: Binding warning, Some generic clips animate transforms that arealready bound by a humanoid avatar. These transforms can only be changed by humanoid cliips (I'm guessing it refers to the basic curve animation I'm using for overall position).

Any idea how to solve this problem or what is the best workflow to work with timeline ?

I'm also having this problem that seems to be a bug:Assertion failed: Transform has SetIsDispatchInterested present when destroying the hierarchy. Systems must deregister themselves in Deactivate.

Same here with unity 2018.2.0f2.
I was on Unity 5.6 and all was working well, then with Unity 2017.1 and Unity 2018.1 all was fine.
But since the update from 2018.1 to 2018.2, all animations are broken in playmode... #T-PoseModeON

All my components are set to Humanoid and I tried to reimports but nothing works

EDIT: The only workaround I found is to Apply changes on the avatar during playmode but it doesn't last when you relaunch